The all-stock deal would value Maxwell at about $218 million, a 55 percent premium over its market value Friday

Tesla will buy the company’s 45.9 million shares for $4.75 a share in an all-stock transaction. The deal represents a 55 percent premium over Maxwell’s closing stock price of $3.07 a share Friday and would value the company at around $218 million.

“We are always looking for potential acquisitions that make sense for the business and support Tesla’s mission to accelerate the world’s transition to sustainable energy,” said Tesla in a statement sent to CNBC.

Maxwell makes ultracapacitors, devices that can store and rapidly deliver surges of energy. Tesla CEO Elon Musk is a fan of the technology for electric cars. Musk has said in the past that the technology could be a more likely source of a breakthrough in electric vehicle technology than batteries. Musk even once said on Twitter that he had planned to conduct research on them at Stanford University.

Maxwell also has a process for making electric battery components that is significantly more efficient than those typically used in the industry. This process could significantly reduce the cost of producing electric vehicles, even when compared with the best battery manufacturing methods available today, Oppenheimer analyst Colin Rusch said in a note sent Monday.

“As TSLA works toward lowering EV prices to expand its addressable market while maintaining [gross margins], we view battery cost, weight, and performance as the key drivers,” Rusch said in the note. Maxwell’s intellectual property in manufacturing “plus applications for its ultracapacitor technology seem likely to be integral in evolving TSLA’s pack design and performance, particularly in heavier vehicles that rely on regenerative braking for system economics.”